Field of the Invention
The present invention relates to an analog-digital conversion circuit drive method, an analog-digital conversion circuit, an imaging device, an imaging system, and an analog-digital conversion circuit inspection method.
Description of the Related Art
An analog-digital conversion circuit is known that includes a plurality of comparators and a plurality of memories respectively corresponding to the plurality of comparators. Each of the plurality of comparators supplies a comparison result signal indicating the result of comparison of signal levels of an analog signal and a reference signal to the memory corresponding to the comparator.
An analog-digital conversion circuit described in Japanese Patent Application Laid-Open No. 2013-65924 includes a counter that supplies a common count signal to a plurality of memories. Each of the memories start sampling the signal level of the count signal at the timing of change in the signal level of the comparison result signal supplied from the corresponding comparator. After the elapse of a predetermined period from the timing of change in the signal level of the comparison result signal, the signal level of the count signal is held. Thus, each of the plurality of memories holds the count signal input to the memory as a digital signal based on the analog signal input to the comparator.